Mild Pyrolysis of Selectively Oxidized Coals. Technical Report, September 1--November 30, 1991

Mild Pyrolysis of Selectively Oxidized Coals. Technical Report, September 1--November 30, 1991
Author:
Publisher:
Total Pages: 20
Release: 1991
Genre:
ISBN:

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.

Mild Pyrolysis of Selectively Oxidized Coals. Technical Report, September 1, 1991--August 31, 1992

Mild Pyrolysis of Selectively Oxidized Coals. Technical Report, September 1, 1991--August 31, 1992
Author:
Publisher:
Total Pages: 34
Release: 1992
Genre:
ISBN:

The primary objective of this study was to evaluate selective oxidation as a pretreatment for the enhanced desulfurization of Illinois Basin coals using a variety of mild thermal/chemical processes. Both an Illinois No. 6 and an Indiana No. 5 coal were selectively oxidized with peroxyacetic acid in the pretreatment step. The products were then treated with many hydroxide and carbonate bases using either water, methanol or ethanol as the solvent system. Other reaction variables investigated include reaction temperature, reaction time, pyrolysis pressure, particle size of the coal and the level of oxidation in the pretreatment step. Throughout the study the selectively oxidized coals were compared to unoxidized control coals. Model compounds were also studied. The results of these studies overwhelmingly show that selective oxidation with peroxyacetic acid significantly enhances the level of desulfurization obtained with subsequent chemical/thermal treatments. Indeed, every process investigated, including simple pyrolysis experiments, showed sulfur removal in the pretreatment step and the subsequent step to be substantially additive. In addition, considerable enhancement in the reactivity of the sulfur in the coal was obtained by the selective oxidation pretreatment. Sulfur contents lower than 0.25% were obtained for selectively oxidized coals. This represents an overall sulfur reduction of around 95%. This is beyond the level required for compliance with Clean Air Act legislation. No unoxidized coal, regardless of the desulfurization treatment, approached this level of sulfur removal.

Mild Pyrolysis of Selectively Oxidized Coals. [Quarterly] Technical Report, December 1, 1991--February 29, 1992

Mild Pyrolysis of Selectively Oxidized Coals. [Quarterly] Technical Report, December 1, 1991--February 29, 1992
Author:
Publisher:
Total Pages: 23
Release: 1992
Genre:
ISBN:

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter primarily concerned establishing the level of selective oxidation required for successful desulfurization in subsequent treatments. Many desulfurization reactions were performed on pretreated as well as unoxidized coal. The results obtained support the following new conclusions: (1) The extent of selective oxidation in the pretreatment step does not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (2) Up to 84% of the sulfur in the IBC 106 coal and 86% of the sulfur in the IBC 106 coal has been removed by combining selective oxidation and SCM/base reactions. (3) Most desulfurizations at 250°C did not produce significant levels of desulfurization. However as the temperature was increased levels of desulfurization increased considerably. (4) Although aqueous base was successful in removing sulfur from both pretreated and untreated samples, the most pronounced desulfurizations were obtained for the untreated samples. This is explained primarily by the dissolution of pyrite in the untreated samples. (5) The best desulfurizations involved SCM and base. Possible synergistic interactions between the methanol and the base are suspected. (6) Overall, selective oxidation pretreatment always led to a lower sulfur product. The severity of desulfurization is reduced by selective oxidation pretreatment.

Energy Resources and Systems

Energy Resources and Systems
Author: Tushar K. Ghosh
Publisher: Springer Science & Business Media
Total Pages: 784
Release: 2009-06-04
Genre: Business & Economics
ISBN: 9048123836

In the lifetimes of the authors, the world and especially the United States have received three significant “wake-up calls” on energy production and consumption. The first of these occurred on October 15, 1973 when the Yom Kippur War began with an attack by Syria and Egypt on Israel. The United States and many western countries supported Israel. Because of the western support of Israel, several Arab oil exporting nations imposed an oil embargo on the west. These nations withheld five million barrels of oil per day. Other countries made up about one million barrels of oil per day but the net loss of four million barrels of oil production per day extended through March of 1974. This represented 7% of the free world’s (i. e. , excluding the USSR) oil production. In 1972 the price of crude oil was about $3. 00 per barrel and by the end of 1974 the price of oil had risen by a factor of 4 to over $12. 00. This resulted in one of the worst recessions in the post World War II era. As a result, there was a movement in the United States to become energy independent. At that time the United States imported about one third of its oil (about five million barrels per day). After the embargo was lifted, the world chose to ignore the “wake-up call” and went on with business as usual.

Mild Pyrolysis of Selectively Oxidized Coals. [Quarterly] Technical Report, March 1, 1992--May 31, 1992

Mild Pyrolysis of Selectively Oxidized Coals. [Quarterly] Technical Report, March 1, 1992--May 31, 1992
Author:
Publisher:
Total Pages: 24
Release: 1992
Genre:
ISBN:

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter primarily concerned the investigation of the desulfurization of the selectively oxidized coals using aqueous or alcoholic base mixtures. Model compound studies were initiated. Results were: Levels of desulfurization obtained in this study are at, or very close to, the 90% removal levels required for these coals to be in compliance with the Clean Air Act legislation; Up to 89.4% of the sulfur in the IBC 101 coal and 88.9% of the sulfur in the IBC 106 coal has been removed by combining selective oxidation and alcoholic/base reactions; Overall, selective oxidation pretreatment always led to a lower sulfur product than the untreated sample; Substantial enhancement in the reactivity of the sulfur in the coal has been achieved by the selective oxidation pretreatment; The highest levels of desulfurization obtained so far all involve bases as additives; The water/Na2CO3 combination, was superior than any of the aqueous hydroxide bases. Possible synergistic interactions between the alcohol and the base are suspected. Over 70% of the sulfur in the IBC 101 coal can be removed by performing vacuum pyrolysis on the selectively oxidized coal. Lower sulfur contents are obtained by lowing the pyrolysis pressure.

Energy Resources and Systems

Energy Resources and Systems
Author: Tushar Ghosh
Publisher: Springer Science & Business Media
Total Pages: 784
Release: 2009-06-17
Genre: Business & Economics
ISBN: 9048123828

In the lifetimes of the authors, the world and especially the United States have received three significant “wake-up calls” on energy production and consumption. The first of these occurred on October 15, 1973 when the Yom Kippur War began with an attack by Syria and Egypt on Israel. The United States and many western countries supported Israel. Because of the western support of Israel, several Arab oil exporting nations imposed an oil embargo on the west. These nations withheld five million barrels of oil per day. Other countries made up about one million barrels of oil per day but the net loss of four million barrels of oil production per day extended through March of 1974. This represented 7% of the free world’s (i. e. , excluding the USSR) oil production. In 1972 the price of crude oil was about $3. 00 per barrel and by the end of 1974 the price of oil had risen by a factor of 4 to over $12. 00. This resulted in one of the worst recessions in the post World War II era. As a result, there was a movement in the United States to become energy independent. At that time the United States imported about one third of its oil (about five million barrels per day). After the embargo was lifted, the world chose to ignore the “wake-up call” and went on with business as usual.

Continuous Bench-scale Tests to Assess METHOXYCOAL Process Performance. Technical Report, September 1--November 30, 1991

Continuous Bench-scale Tests to Assess METHOXYCOAL Process Performance. Technical Report, September 1--November 30, 1991
Author:
Publisher:
Total Pages: 20
Release: 1991
Genre:
ISBN:

Laboratory-scale research conducted at Southern Illinois University at Carbondale (SIUC) has shown that coal pyrolysis in the presence of CH4 and small quantities of O2 (the METHOXYCOAL process) can produce high yields of liquids and valuable chemicals compared to conventional pyrolysis. The addition of MgO, coal ash, and clays have been shown to further enhance coal conversion. The goal of this two-year project is to build upon that laboratory research by conducting continuous bench-scale tests at IGT. Tests are being conducted with IBC-101 coal under CH4/O2 blends with and without added coal ash, MgO, and/or clays, at temperatures and pressures up to 1000°F and 200 psig. These tests will provide data to select preferred operating conditions for chemicals production from high-sulfur Illinois coals.