Recent Patents on Chemical Engineering - Volume 5, Issue 2, 2012

Synthesis gas serves as a raw material for a variety of processes such as methanol production, Fischer-Tropsch synthesis of hydrocarbons or hydroformylation reactions. It can be obtained by reforming hydrocarbons, in particular methane, by gasification of coal or by conversion of biomass. Biomass can be gasified either directly or after pretreatment, e.g. by pyrolysis. The use of biomass as feedstock, especially waste biomass, is favorable since its availability is, in contrast to fossil resources, not exhaustible, and it can contribute to a decrease of CO2 emissions. A prominent strategy is the production of methanol, ethanol or dimethyl ether (DME) from biomass-derived, i.e. carbon monoxide-rich, synthesis gas. These are valuable fuels and chemicals, which can be converted to a series of other products. Within this article recent developments in the synthesis of ethanol and higher alcohols as well as DME from biomass-derived synthesis gas are surveyed with a strong focus on the patent literature from the year 2000 onwards. Furthermore, processes employing methanol as feedstock, e.g. synthesis of olefins and gasoline, are also evaluated.

The high production cost of traditional photovoltaic materials, along with the environmental problems ensuing from the production and processing thereof, constitutes a serious drawback for the commercialization of photovoltaic cells. Many concerted efforts have been made in order to develop materials in thin film form able to guarantee optimal characteristics in terms of abundance, environmental compatibility, and photoactivity. For the past three decades, several investigations have highlighted the potential of iron disulphide (pyrite) as a viable candidate for future production of solar cells on a large scale. Based on important disclosed patents, the present article focuses on the review and discussion of fabrication methods of pyrite in thin film form for solar photovoltaics.

In recent years, many investigations have been accomplished to improve the efficiency of starchy wastewater treatment systems. In order to achieve stringent discharge standards, several methodologies have been applied that are included from using traditional activated sludge systems to modern membrane technologies. On the other hand, high rate of population growth has created rising rate of consumption, rising rate of pollution generation, and more demands for resources. So, making an assessment on the starchy wastewater treatment processes to select the more efficient one seems to be necessary. Generally, starchy wastewater treatments are divided into three main subsets: (i) biological, (ii) chemical, and (iii) physical methods, and also in some cases a hybrid system has been used. In this work, the methods applied in recent papers and patents for treating starchy wastewater around the world have been reviewed.

Many patents are available claiming the process for Diglyceride or Diacylglycerol (DAG) oil production through chemical and enzymatic approaches. The methods are esterification, glyceroloysis, hydrolysis, interesterification, and transesterification. Almost all the reactions used edible oil as a starting material. Majority of the inventors have patented their research for DAG production in relation with certain products such as margarine, mayonnaise, shortening, Omega-3 and others. This present review describes a selection of recent patents of DAG production and its applications.

Membrane processes exist for most of the fluid separations encountered in industry. The most widely used is membrane ultrafiltration, pressure driven process which is capable of separating particles in the approximate size range of 0.001 to 0.1 μm. The design of membrane separation processes, like all other processes, requires quantitative expressions relating material properties to separation performance. The factors controlling the performance of ultrafiltration are extensively reviewed. There have been a number of seminal approaches in this field. Most have been based on the rate limiting effects of the concentration polarization of the separated particles at the membrane surface. Various rigorous, empirical and intuitive models exist, which have been critically assessed in terms of their predictive capability and applicability. The decision as to which of the membrane filtration models is the most correct in predicting permeation rates is a matter of difficulty and appears to depend on the nature of the solute and membrane composition. This patent review highlights the applicability of such models to ultrafiltration.

The preparation of chemically modified activated cashew nut shell (ACNSB) of different impregnation ratios and their effects in adsorption of benzene vapor were studied. Effects of chemical pre-impregnation using phosphoric acid at different ratios (1:1 and 2:1) were investigated in order to patent. Physico-chemical characterization including surface area, scanning electron microscopy, energy dispersive X-ray spectroscopy, High-resolution Transmission Electron Microscopy and Fourier transform infrared spectroscopy of the ACNSB before and after benzene adsorption have been done to understand the adsorption mechanism. Optimum conditions for benzene removal were found to be, adsorbent dose m=10 g/l of solution and time (t) 120 min for the C0 range of 300–500 mg/l. Adsorption of benzene followed pseudosecond- order kinetics. Langmuir and R–P isotherms were found to best represented data for benzene adsorption onto ACSNB. In ACNSB column experiments, it can be concluded that concentration of benzene increases with the longer breakthrough time and hence higher adsorption capacity. ACSNB are many advantages includes simple and fast, organic solvent recovery, economical, energy savings, environmentally safe aspect and minimize the waste management problem.

Energy crisis is one of the most urgent tasks of today, and the utilization of solar power is regarded as one powerful way to solve this problem. In this aspect, titanium dioxide (TiO2) is especially interesting as it is an efficient material that can convert solar power into energies that can be directly used in our daily life. Consequently, various studies and patents relating to the preparation and modification of TiO2 have been reported and issued, to accelerate its practical application. In this work, we synthesized nano-sized TiO2 particles by hydrothermal method under different conditions and investigated its photocatalytic performances for degradation of ethane. Results indicated that for solvents neutral water, acidic water and ethanol, only use neutral water could the product possesses mesoporous structure. Further studies indicated that the particle size increases and the surface area decreases with increasing the calcination temperature. The TiO2 hydrolyzed at 100 °C and calcined at 500 °C showed average particle size of 13.5 nm and surface area of 73 m2/g. No obvious change in the textural properties was observed, but an increase in the surface hydroxyl groups was found for TiO2 hydrolyzed at different temperatures. Photocatalytic tests on C2H4 degradation reaction (C2H4 → CO2) indicated that the TiO2 synthesized in this work is more active than the standard Degussa P25 TiO2, in particular for the one hydrolyzed at high temperature (i.e. 120 °C), which possesses the largest amount of surface hydroxyl groups.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different nanotechnology methods, processes and techniques involved....