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Evaluation of rice straw for purification of lovastatin, TAPPI Journal November 2021
ABSTRACT: Cholesterol synthesis in the human body can be catalyzed by the coenzyme HMG-CoA reductase, and lovastatin, a key enzyme inhibitor, can reduce hypercholesterolemia. Lovastatin can be obtained as a secondary metabolite of Aspergillus terreus ATCC 20542. In this study, rice straw of lignocellulose was used in aeration and agitation bath fermentation in a 1-L flask, and a maximal crude extraction rate of 473 mg/L lovastatin was obtained. The crude extract was treated with silica gel (230•400 mesh) column chromatography. Ethyl acetate/ethanol (95%) was used as the mobile phase, and isolation was performed through elution with various ethyl acetate/ethanol ratios. The highest production rate of 153 mg/L was achieved with ethyl acetate/ethanol in a ratio of 8:2. The lovastatin gained from the crude extract was added to 12 fractions treated with 0.001 N alkali, and acetone was then added. After 24 h of recrystallization at 4°C, the extract underwent high-performance liquid chromatography. The purity had increased from 25% to 84.6%, and the recovery rate was 65.2%.
Journal articles
Magazine articles
Control of malodorous gases emission from wet-end white water with hydrogen peroxide, TAPPI Journal October 2021
ABSTRACT: White water is highly recycled in the papermaking process so that its quality is easily deteriorated, thus producing lots of malodorous gases that are extremely harmful to human health and the environment. In this paper, the effect of hydrogen peroxide (H2O2) on the control of malodorous gases released from white water was investigated. The results showed that the released amount of total volatile organic compounds (TVOC) decreased gradually with the increase of H2O2 dosage. Specifically, the TVOC emission reached the minimum as the H2O2 dosage was 1.5 mmol/L, and meanwhile, the hydrogen sulfide (H2S) and ammonia (NH3) were almost completely removed. It was also found that pH had little effect on the release of TVOC as H2O2 was added, but it evidently affect-ed the release of H2S and NH3. When the pH value of the white water was changed to 4.0 or 9.0, the emission of TVOC decreased slightly, while both H2S and NH3 were completely removed in both cases. The ferrous ions (Fe2+) and the copper ions (Cu2+) were found to promote the generation of hydroxyl radicals (HOœ) out of H2O2, enhancing its inhibition on the release of malodorous gases from white water. The Fe2+/H2O2 system and Cu2+/H2O2 system exhibited similar efficiency in inhibiting the TVOC releasing, whereas the Cu2+/H2O2 system showed better perfor-mance in removing H2S and NH3.
Journal articles
Magazine articles
Recovery boiler back-end heat recovery, TAPPI Journal March 2023
ABSTRACT: Sustainability and efficient use of resources are becoming increasingly important aspects in the operation of all industries. Recently, some biomass-fired boilers have been equipped with increasingly complex condensing back-end heat recovery solutions, sometimes also using heat pumps to upgrade the low-grade heat. In kraft recovery boilers, however, scrubbers are still mainly for gas cleaning, with only simple heat recovery solutions. In this paper, we use process simulation software to study the potential to improve the power generation and energy efficiency by applying condensing back-end heat recovery on a recovery boiler. Different configurations are considered, including heat pumps. Potential streams to serve as heat sinks are considered and evaluated. Lowering the recovery boiler flue gas temperature to approximately 65°C significantly decreases the flue gas losses. The heat can be recovered as hot water, which is used to partially replace low-pressure (LP) steam, making more steam available for the condensing steam turbine portion for increased power generation. The results indicate that in a simple condensing plant, some 1%•4% additional electricity could be generated. In a Nordic mill that provides district heating, even more additional electricity generation, up to 6%, could be achieved. Provided the availability of sufficient low-temperature heat sinks to use the recovered heat, as well as sufficient condensing turbine swallowing capacity to utilize the LP steam, the use of scrubbing and possibly upgrading the heat using heat pumps appears potentially useful.
Journal articles
E-commerce: panacea or placebo?, TAPPI JOURNAL, July 2001, Vol. 84(7)
E-commerce: panacea or placebo?, TAPPI JOURNAL, July 2001, Vol. 84(7)
Journal articles
Bleaching of recycled fibers by adding sodium borohydride to a peroxide reinforced oxygen stage, TAPPI JOURNAL, June 2001, Vol. 84(6)
Bleaching of recycled fibers by adding sodium borohydride to a peroxide reinforced oxygen stage, TAPPI JOURNAL, June 2001, Vol. 84(6)
Journal articles
Are your thermowells safe?, TAPPI JOURNAL, April 2002 (270KB), (TAPPI JOURNAL APRIL 2002)
Are your thermowells safe?, SOLUTIONS! & TAPPI JOURNAL, April 2002 (270KB)
Journal articles
Research and development in the pulp and paper industry: year 2000 and beyond, TAPPI JOURNAL, January 2000, Vol. 83(1)
Research and development in the pulp and paper industry: year 2000 and beyond, TAPPI JOURNAL, January 2000, Vol. 83(1)
Journal articles
Changing times for mill industries: integration of business and manufacturing information, TAPPI JOURNAL, January 2000, Vol. 83(1)
Changing times for mill industries: integration of business and manufacturing information, TAPPI JOURNAL, January 2000, Vol. 83(1)
Journal articles
Investing in the future of your mill, TAPPI JOURNAL, July 2000, Vol. 83(7)
Investing in the future of your mill, TAPPI JOURNAL, July 2000, Vol. 83(7)
Journal articles
The use of ozone as a biocide in paper machine recycled white water, TAPPI JOURNAL, May 2000, Vol. 83(5)
The use of ozone as a biocide in paper machine recycled white water, TAPPI JOURNAL, May 2000, Vol. 83(5)