| Start of section
Production, amateur Radio amateurs Aircraft model, rocket-model Useful, entertaining |
Stealth Master
Electronics Physics Technologies Inventions |
Secrets of the cosmos
Secrets of the Earth Secrets of the Ocean Tricks Map of section |
  |
| Use of the site materials is allowed subject to the link (for websites - hyperlinks) | |||
Navigation: => |
Home / Patent catalog / Catalog section / Back / |
|
INVENTION
Patent of the Russian Federation RU2131909
A METHOD FOR OBTAINING AN ENVIRONMENTALLY CLEAN HIGH-OCTANE GASOLINE
The name of the inventor: Sayfullin N.R .; Kalimullin M.M .; Navalikhin PG; R. Salikhov; Telyashev GG; Akhmetov AF; Abdulminev K.G .; Makhov A.F .; Maltsev AP; Emelyanov V.E .; Nikitina E.A.
The name of the patent holder: Open Joint-Stock Company Novo-Ufimsky Oil Refinery; Ufa State Oil Technical University
Address for correspondence: 450037, Ufa, Open Joint-Stock Company Novo-Ufa Oil Refinery, Patent Office
Date of commencement of the patent: 1998.07.01
The method for producing ecologically pure high-octane gasoline is described, which includes preliminary hydrotreating of straight-run gasoline, rectification of the hydrogenate to produce a boiling and boiling fraction, isomerization of the first fraction and catalytic reforming of the second fraction, fractionation of the catalytic reforming part of gasoline to obtain the desired fraction, mixing of the obtained catalytic reformate gasoline fraction, alkylate And isomerate, characterized in that 40 to 80 wt. % Of catalytic reforming gasoline to obtain a fraction boiling in the temperature range of NK-85 ° C, part of which is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process - not more than 5 wt. %, The remaining part of the NC-85 ° C fraction of the catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300 to 400 ° C and a pressure of 2.5 to 3.5 MPa, Catalytic reforming gasoline boiling at a temperature of 130 ° C -CK and mixing a fraction of 130 ° C-CK of catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio, by weight, %: 15 - 45: 1 - 40: 5 - 40: 3 - 30, respectively. The technical result is the improvement of the quality of the target product.
DESCRIPTION OF THE INVENTION
The invention relates to the production of motor fuels, in particular the production of high-octane gasoline, and can be used in the oil refining industry.
A method for producing high octane gasoline by catalytic reforming of a straight-run gasoline fraction is known, followed by fractionation of 30-90% of the obtained reforming gasoline, with the separation of fractions boiling in the temperature ranges 35-150 ° C and 100-190 ° C and mixing them with alkylbenzene and the head straight-run fraction RU, Patent No. 2009168, C 10 G 59/00, 1992).
The disadvantage of this method is the low octane number of produced fuels, therefore, the preparation of commercial fuels requires the addition of ethyl liquid.
A method for producing high-octane gasoline by catalytic reforming of a straight-run gasoline fraction is known, fractionating 30-90% of catalytic reforming gasoline with separation of a fraction boiling in the temperature range of 35-150 ° C and subsequent mixing of the recovered fraction with catalytic reforming gasoline and alkylate in an amount of 40-70, 10-30 to 100% by weight of the mixture, respectively (RU, Patent No. 2009167, C 10 G 59/00, 1992).
However, this method does not allow to obtain gasoline with an octane number of 95, 98 points without adding ethyl liquid.
The closest technical solution to the claimed invention is a method for producing high octane gasoline by preliminary hydrotreatment of a straight-run gasoline fraction of NK-160 ° C at a temperature of 330-380 ° C, a pressure of 3.3-3.7 MPa in the presence of a nickel-molybdenum catalyst, fractionating the hydrogenated oil to obtain fractions NK-85 ° C and 85 ° C -CK, isomerization of the NK-85 ° C fraction at a temperature of 250-280 ° C, a pressure of 2.5-2.8 MPa in the presence of an alumoplatinum catalyst, catalytic reforming of the 85 ° C -CK fraction, Fractionation of 10-40% by weight of catalytic reforming gasoline to obtain a catalytic reforming gasoline fraction boiling in a temperature range of 110 ° C to KC, mixing a 110 ° C fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate and isomerizate in a ratio, %: 15-40, 30-60, 15-40, 5-15, respectively, and additionally introducing into the desired product 1-15% by weight of ethers of C 1 -C 5 alcohols or mixtures thereof with lower alcohols C 1 -C 4 ( RU, Patent No. 2078792, C 10 G 63/00, 1997 - prototype).
The disadvantage of this method of obtaining high-octane gasoline is an increased content of aromatic hydrocarbons in the target product (37.9-44.4 vol.%) And low volatility - 10 and 50% of the volume of gasoline boils at temperatures close to the maximum permissible values of currently effective standards (75 and 120 ° C, respectively).
Since 01.01.99 the new GOST 51105-97 "Fuels for internal combustion engines." Unleaded gasoline has been introduced. " This standard sets very strict requirements for the volatility of gasolines. The volume of evaporated gasoline at a temperature of 70 ° C should be at least 15%, the volume of evaporated gasoline at a temperature of 100 ° C - not less than 40%, which will require the involvement of high-octane gasoline in the composition of a significant number of low-boiling gasoline fractions.
In addition, restrictive requirements for the content of aromatic hydrocarbons (no more than 35% vol.) Are imposed on promising motor gasoline competitive in the European and world markets; A particularly stringent requirement is made for the content of the most toxic of aromatic hydrocarbons - benzene. The technical goal of the invention is to improve the quality of the target product by improving its ecological characteristics, detonation and starting properties by reducing the content of aromatic hydrocarbons, including the most toxic of them - benzene, and low-octane paraffin hydrocarbons C 7 -C 9 .
The essence of the invention consists in the fact that in the known method for producing high-octane gasoline by preliminary hydrotreating of straight-run gasoline, rectifying the hydrogenate to produce a low-boiling and heavily boiling fraction, isomerization of the first fraction and catalytic reforming of the second fraction, fractionation of a portion of the catalytic reforming gasoline to obtain the desired fraction, mixing the obtained fraction Gasoline, catalytic reforming gasoline, catalytic reforming gasoline, alkylate and isomerate, according to the invention, 40-80% by weight of catalytic reforming gasoline is subjected to fractionation to obtain a fraction boiling in the temperature range of 85 ° C, part of which is mixed with the low-boiling fraction of hydrogenated hydrogenate in an amount providing The permissible content of benzene in the feed mixture of the isomerization process is not more than 5% by weight, the remaining part of the NK-85 ° C fraction of the catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300-400 ° C and a pressure of 2.5-3.5 MPa, a catalytic reforming gasoline fraction is evolved which boils out at a temperature of 130 ° C to KC and a fraction of 130 ° C is carried out - the catalytic reforming gasoline CS, the catalytic reforming gasoline, alkylate, isomerizate and / Or hydroisomerizate in a ratio of 15-45, 1-40, 5-40, 3-30, respectively, to the desired product, in some cases, in addition, 1.0-15.0% by weight of the C 1 - C 5 or mixtures thereof with lower alcohols C 1 -C 4
Studies have shown that in the NK-85 ° C fraction of catalytic reforming gasoline, which has the necessary starting properties, contains 16.9% benzene. In this connection, it is proposed to subject the fraction to additional processing for the removal of benzene in the following two directions before compounding of commercial ecologically clean high-octane gasolines;
- part of the fraction of NC-65 o C of catalytic reforming gasoline is mixed with the low-boiling fraction of hydrogenated in an amount that provides an allowable total content of benzene in the feed mixture of the isomerization process - no more than 5% by weight;
- the remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300-400 ° C and a pressure of 2.5-3.5 MPa.
Studies have shown that the 130 ° C fraction of the catalytic reforming gasoline contains 3 times less in comparison with the 110 ° C-catalytic reforming gasoline catalytic reforming fraction (prototype) of low-octane paraffin hydrocarbons C 7 -C 9 (12.4% and 4.1% %, Respectively), the average octane number of which is minus 20 points, with no benzene completely. The octane number of the fraction of 130 ° C KK reaches 98 points by the motor method (more than in the fraction 110 ° C - KK, having an octane number of 91.8 m.
The method is carried out as follows. The straight-run gasoline fraction of NK-160 ° C is hydrotreated at a temperature of 330-350 ° C, a pressure of 3.3-3.7 MPa in the presence of a nickel-molybdenum catalyst and then fractionated to obtain a low-boiling fraction of NK-85 ° C and a heavy boiling fraction of 85 ° C- The first fraction is isomerized to form isomerizate at a temperature of 250-280 ° C, a pressure of 2.5-2.8 MPa in the presence of an alumoplatinum catalyst, and the second fraction is subjected to catalytic reforming, then 40-80% by weight of catalytic reforming gasoline is fractionated To obtain fractions of catalytic reforming gasoline boiling in the temperature ranges of NK-85 ° C and 130 ° C-KK.
Further, a portion of the HC-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-no more than 5% by weight. The remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300-400 ° C and a pressure of 2.5-3.5 MPa. The desired product is obtained by mixing a 130.degree. C.C. fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerate and / or hydroisomerizate in a weight ratio. %: 15-45, 1-40, 5-40, 3-30, respectively. In the desired product it is proposed and, in some cases, additionally 1-15% by weight of C 1 -C 5 alcohols or their mixtures with lower alcohols C 1 -C 4 .
The content of aromatic hydrocarbons in the target product is 34.8-41.6% vol. %, Including benzene 0-0.5 vol%, against 37.9-44.4 vol% and 0.6-1.1 vol%, respectively (prototype).
The octane number of the target product reaches 87.9-93 points by the motor method, compared to 87.2-88.9 points in the MM. (prototype). The starting properties of the target product are improved - 10% and 50% of the gasoline volume evaporates at a temperature of 60 ° -64 ° C against 74 ° C and 108-122 ° C against 110 ° -118 ° C (prototype). The content of low-octane paraffinic hydrocarbons C 7 -C 9 in the target product is 1.8-6.1% versus 7.6.10.8% (prototype).
A distinctive feature of the claimed technical solution is the separation of the fractions of catalytic reforming gasoline boiling in the temperature range of NK-85 ° C and 130 ° C -CK, mixing part of the NK-85 ° C fraction of catalytic reforming gasoline with the low-boiling fraction of hydrogenated hydrogenate in an amount that provides the allowable total The content of benzene in the feed mixture of the isomerization process is not more than 5% by weight, the hydroisomerization of the remaining part of the NK-85 ° C fraction of the catalytic reforming gasoline in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300-400 ° C and Pressure of 2.5-3.5 MPa and subsequent mixing of a fraction of 130 ° C. with a gasoline of catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio of 15-45, 1-40, 40, 3-30, respectively, in an additional addition of 1.0-15.0% by weight of C 1 -C 5 alcohols or their mixtures with lower alcohols C 1 -C 4 .
Exemplary embodiments of the claimed invention.
Example 1 . The straight-run gasoline fraction of NK-160 ° C (oil or gas condensate) is hydrotreated at a temperature of 300-350 ° C, a pressure of 3.3-3.7 MPa in the presence of a nickel-molybdenum catalyst, then fractionated to obtain a low-boiling fraction of NK-85 ° C And a heavy boiling fraction of 85 ° C-KC, the characteristics of which are presented in Table 1.
The first fraction is isomerized to form an isomerizate at a temperature of 250-280 ° C, a pressure of 2.5-2.8 MPa in the presence of an alumoplatinum catalyst, and the second fraction is subjected to catalytic reforming at a temperature of 520 ° C, a pressure of 2.0 MPa, Raw material 1.6 h -1 and the multiplicity of circulation of hydrogen-containing gas 1200 nm 3 / m 3 . Catalytic reforming gasoline is obtained, 40% of which is fractionated to recover fractions boiling in the temperature range of 85 ° C and 130 ° C to the KC. Further, a portion of the NK-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling fraction of hydrogenated hydrogenate in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-there was no 5 wt. %. The remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 300 ° C. and a pressure of 2.5 MPa. Characteristics of the raw mixture of the isomerization process, isomerizate, catalytic reforming gasoline, NK-85 ° C fractions and 130 ° C-catalytic reforming catalytic reforming catalytic converter, alkylate and hydroisomerization product of the NK-85 ° C fraction of catalytic reformer-hydroisomerizate gasoline is presented in Table 1.
The desired product is obtained by mixing a 130.degree . C. fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio, wt.%: 17, 40, 40, 3, respectively. The characteristics of the product and product of the known process are shown in Table 2.
The aromatic hydrocarbon content of the target product is 34.8% by volume, lower than the aromatic hydrocarbon content of the desired product obtained in a known manner (Table 2) below and the content of low-octane paraffin hydrocarbons C 7 -C 9 and the most toxic of benzene aromatic hydrocarbons ; Higher octane number and improved starting properties of the product.
Example 2 . The straight-run gasoline fraction of NK-160 ° C is hydrotreated under the conditions of Example 1, then fractionated to obtain a low-boiling fraction of NK -85 ° C and a heavy boiling fraction of 85 ° C -CK. The first fraction is isomerized under the conditions of Example 1 to form an isomerizate and the second fraction is subjected to catalytic reforming under the conditions of Example 1. Catalyst reforming gas is obtained, 80% of which is fractionated to recover fractions boiling in the temperature range of 85 ° C and 130 ° C - QA. Further, a portion of the HC-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-no more than 5% by weight. The remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 400 ° C and a pressure of 3.5 MPa. Characteristics of the feed mixture of isomerization process, isomerizate, catalytic reforming gasoline, NK-85 ° C fractions and 130 ° C-catalytic reforming catalytic reforming catalytic converter, alkylate and hydroisomerization product of the NK-85 ° C fraction of catalytic reformate-hydrogenated gasoline are presented in Table 1. The target product Are obtained by mixing a 130 ° C fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio, % 45, 1, 24, 30, respectively. The characteristics of the product obtained are shown in Table 2.
The content of aromatic hydrocarbons in the target product is 40.6% vol. %, Lower than the content of aromatic hydrocarbons in the desired product obtained by the known method (Table 2), below and the content of low-octane paraffin hydrocarbons C 7 -C 9 and the most toxic of aromatic hydrocarbons of benzene; Higher octane number and improved starting properties of the product.
Example 3 . The straight-run gasoline fraction of NK-160 ° C is hydrotreated under the conditions of Example 1, then fractionated to obtain a low-boiling fraction of NK-85 ° C and a heavy boiling fraction of 85 ° C -CK. The first fraction is isomerized under the conditions of Example 1 to form an isomerizate, and the second fraction is subjected to catalytic reforming under the conditions of Example 1. Catalyst reforming gas is obtained, 60% of which is fractionated to recover fractions boiling in the temperature range of 85 ° C and 130 ° C - QA. Further, a portion of the HC-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-no more than 5% by weight. The remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 350 ° C. and a pressure of 3.0 MPa. Characteristics of the feed mixture of the isomerization process, isomerizate, catalytic reforming gasoline, NK-85 ° C fractions and 130 ° C-catalytic reforming catalytic reforming catalytic converter, alkylate and the hydroisomerization product of the fractions of NK-85 ° C of catalytic reformate-hydroisomerizate gasoline are presented in Table 1.
The desired product is obtained by mixing the 130.degree . C. fraction of the catalytic reforming gasoline CS, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate by weight ratio: 40, 25, 5, 30, respectively. The characteristics of the product obtained are shown in Table 2.
The content of aromatic hydrocarbons in the target product is 40.2% by volume, lower than the content of aromatic hydrocarbons in the desired product obtained by the known method (Table 2), below and the content of low-octane paraffin hydrocarbons C 7 -C 9 and the most toxic of aromatic hydrocarbons Benzene; Octane number and improved starting properties of the product.
Example 4 . The straight-run gasoline fraction of NK-160 ° C is hydrotreated under the conditions of Example 1, then fractionated to obtain a low-boiling fraction of NK-85 ° C and a heavy-boiling fraction of 85 ° C -CK. The first fraction is isomerized under the conditions of Example 1 to form an isomerizate and the second fraction is subjected to catalytic reforming under the conditions of Example 1. Catalyst reforming gas is obtained, 70% of which is fractionated to recover fractions boiling in the temperature range of 85 ° C and 130 ° C - QA. Further, a portion of the HC-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-no more than 5% by weight. The remaining part of the NK-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 360 ° C. and a pressure of 3.5 MPa. Characteristics of the raw mixture of the isomerization process, isomerizate, catalytic reforming gasoline, NK-85 ° C fractions and 130 ° C-catalytic reforming catalytic reforming catalytic converter, alkylate and hydroisomerization product of the NK-85 ° C fractions of catalytic reformate-hydroisomerizate is shown in Table 1. The target product Is obtained by mixing a 130.degree . C. fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio of 15 wt%, 30, 35, 20 wt%, respectively, to the product obtained, 10 wt% of ethers Alcohols C 1 -C 5 or mixtures thereof with lower alcohols C 1 -C 4 . The characteristics of the product obtained are shown in Table 2.
The content of aromatic hydrocarbons in the target product is 38 vol. %, Lower than the content of aromatic hydrocarbons in the desired product obtained by the known method (Table 2), below and the content of low-octane paraffinic hydrocarbons C 7 -C 9 and the most toxic of aromatic hydrocarbons-benzene; Higher octane number and improved starting properties of the product.
Example 5 . The straight-run gasoline fraction of NC-160 ° C is hydrotreated under the conditions of Example 1. Then, fractionation to obtain a low-boiling fraction of NK-85 ° C and a heavy boiling fraction of 85 ° C -CK. The first fraction is isomerized under the conditions of Example 1 to form an isomerizate and the second fraction is subjected to catalytic reforming under the conditions of Example 1. Catalyst reforming gasoline is obtained, 50% of which is fractionated to recover fractions boiling in the temperature range of 85 ° C and 130 ° C - QA. Further, a portion of the HC-85.degree . C. fraction of the catalytic reforming gasoline is mixed with the low-boiling hydrogenogenate fraction in an amount providing an allowable total benzene content in the feed mixture of the isomerization process-no more than 5% by weight. The remaining part of the HC-85 ° C fraction of catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing Group VIII metals on alumina at a temperature of 350 ° C. and a pressure of 2.5 MPa. Characteristics of the raw mix of isomerization process, isomerizate, catalytic reforming gasoline, NK-85 ° C fractions and 130 ° C-catalytic reforming catalytic reforming catalytic converter, alkylate and hydroisomerization product of the NK-85 ° C fraction of catalytic reformate-hydroisomerizate gasoline is presented in Table 1. The target product Are obtained by mixing a 130 ° C fraction of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or hydroisomerizate in a ratio, %: 45, 1, 40, 14 respectively. The characteristics of the product obtained are shown in Table 2.
The content of aromatic hydrocarbons in the target product is 41.6% vol. %, Lower than the content of aromatic hydrocarbons in the target product obtained by the known method (Table 2), below and the content of low-octane paraffinic hydrocarbons C 7 -C 9, and the most toxic of aromatic hydrocarbons-benzene; Higher octane number and improved starting properties of the product. From the data presented in Table 2, it can be seen that the proposed method makes it possible to improve the quality of the desired product by reducing the content of aromatic hydrocarbons, including the most toxic of aromatic hydrocarbons, benzene, and the content of low-octane paraffin hydrocarbons C 7 -C 9 ; Increase the octane number and improve the starting properties of the product.
The proposed invention can be used in oil refineries for the production of high-octane ecological clean gasoline competing with similar gasoline of the European standard.
Further advantages of the proposed method in comparison with the known method are:
1. Increase in the production of high-octane environmentally friendly gasoline by expanding the resources of components involved in the preparation of high-quality commercial products.
2. The use of the target product for road transport will reduce harmful emissions into the atmosphere, that is, reduce environmental pollution.
CLAIM
1. A process for producing ecologically pure high-octane gasoline, comprising: preliminary hydrotreating of straight-run gasoline; rectifying the hydrogenate to produce a light-boiling and heavy-boiling fraction, isomerizing the first fraction and catalytic reforming of the second fraction; fractionating the catalytic reforming portion of gasoline to obtain the desired fraction; mixing the obtained catalytic reforming gasoline fraction; Gasoline, catalytic reforming gasoline, alkylate and isomerizate, characterized in that 40 to 80% by weight of catalytic reforming gasoline is subjected to fractionation to obtain a fraction boiling in an interval of temperatures of NK-85 ° C, part of which is mixed with a low-boiling fraction of hydrogenated hydrogenate in an amount providing an allowable total The benzene content in the feed mixture of the isomerization process is not more than 5% by weight, the remaining portion of the FC-85 ° C fraction of the catalytic reforming gasoline is hydroisomerized in a separate reactor in the presence of a catalyst containing metals of Group VIII on alumina at a temperature of 300-400 ° C And a pressure of 2.5 to 3.5 MPa, a catalytic reforming gasoline fraction boiling out at a temperature of 130.degree.C. to -C.sup. Is separated out, and a fraction of 130.degree . C.-FA of the catalytic reforming gasoline, catalytic reforming gasoline, alkylate, isomerizate and / or Hydroisomerizate in a ratio, by weight, of 15 to 45: 1 to 40: 5 to 40: 3 to 30, respectively.
2. A process according to claim 1, characterized in that 1.0 to 15.0% by weight of C 1 -C 5 alcohols or their mixtures with lower alcohols C 1 -C 4 are additionally added to the desired product.
print version
Date of publication 07.04.2007gg
Comments
Commenting on, remember that the content and tone of your message can hurt the feelings of real people, show respect and tolerance to your interlocutors even if you do not share their opinion, your behavior in the conditions of freedom of expression and anonymity provided by the Internet, changes Not only virtual, but also the real world. All comments are hidden from the index, spam is controlled.