Recent Patents on Chemical Engineering - Volume 3, Issue 1, 2010

Surface properties of polymeric membranes are of fundamental importance in many branches of industrial applications (e.g. separation of gases, liquid mixtures, filtration, water treatment, desalination, medicine etc.). Hence, it is natural that much attention has been paid to the membrane surface modification. Review of the patents that have appeared since the year 2000 concerning the surface modification of the polymeric and other synthetic membranes was made in this article by classifying them according to the modification method. The surface modification of synthetic membranes can be performed; i) by blending or adding some other component(s) into the host polymeric material, ii) by coating the surface of the membrane with some other polymer including grafting and in situ polymerization, iii) by altering the membrane surface via chemical reaction iv) by radiation via high energy particles, and, v) by other methods. It should be noted that most of surface modification was done for the membranes used in water treatment and liquid filtration to reduce fouling and to enhance membrane performance. In contrast, very few are found in the field of gas separation. This is because surface modification is thought to have stronger impact on the performance of water treatment membranes such as RO/NF/UF/MF membranes. On the other hand, in gas treatment membranes the role of membrane surface in gas transport is less emphasized. This, however, will change as the membrane scientists and engineers will recognize the role of surface flow in the gas and vapour transport and attempt to utilize these phenomena in practical separation processes. This is already happening in the field of molecular sieve and carbon nano-tube membranes. As well, the surface phenomena will play a pivotal role in reducing the aging phenomena of gas separation membrane. The surface modification technique will also be used in other separation processes such as vapour separation and membrane distillation in the future, as shown by some examples.

Since early 1990s functional foods have presented important attention and demand from scientist and general population. Among the different components of functional foods, prebiotics have demonstrated a wide range of beneficial properties such as favoring of probiotic bacteria growth and intestinal mineral absorption. The most used prebiotics are inulin-type fructans and galactooligosaccharides (GOS). Although the former are widely used in nutritional supplements and functional foods and drinks, GOS have started to emerge as important prebiotic compounds since they share most of the prebiotic characteristic of inulin-type fructans but can be synthesized from cheaper substrates like whey. GOS are produced by the transgalactosylating activity of β-galactosidases (β-gal) derived from microorganisms, mainly fungi. In this paper, the recent patents in β-gal and GOS production and their applications will be discussed. About 47 patents regarding β-gal and GOS production and applications have been published since 2000, which are lower than those observed for other prebiotic compounds, like inulin-type fructans. Patents include the production of GOS with native or recombinant enzymes, the production of β-gal resistant to low or high temperatures and the development of functional foods and cosmetics. β-gal and GOS production represent an important but partially explored field for the development of new prebiotic compounds and their applications.

Oxidative desulfurization (ODS) process, a non-hydrogen consuming method to remove sulfur from liquid fuels, has received a lot of attention recently for desulfurization of some liquid fuel feedstocks. This paper reviewed the recent patents in the ODS process. Generally Hydrogen peroxide (H2O2) is used as an oxidant in organic acids (e.g., acetic acid or formic acid) medium for the ODS process. Compared with the traditional hydrodesulfurization (HDS) process, ODS process has two main advantages: 1) the ODS process can be carried out in liquid phase under very mild operating conditions, thus much less capital intensive; 2) this process shows high reactivity and selectivity for some sulfide compounds which are hard to be removed by the HDS process, e.g. dibenzothiophene (DBT) and its derivatives. After the oxidation, the sulfur compounds are oxidized to their corresponding sulfoxides and subsequently sulfones. Afterward, these highly polarized products can be removed by solvent extraction or sorbent adsorption. Other oxidants, such as t-Butyl hydroperoxide, air, and solid catalyst were also reviewed. Ultrasound greatly facilitates the ODS process. The ODS process is quite useful for small and medium refineries, and also a good fit as a finishing process for downstream of an existing HDS unit producing 300-500 ppm sulfur.

Ceramic membranes are a relatively new technology being developed in the filtration field. The following article comprises a thorough patents review on the topic from 2001 up to the present. Their importance lies on ceramic materials durability when well-employed, their resistance to high temperature operations and aggressive media, and the wide applications range they present. The patents surveyed have been classified in groups, depending on the separation being carried out in each case. The first group identified is “gas-gas streams”, where gas separation was considered. Others such as “liquid-liquid streams”, where water treatment and ammonia purification, for instance, are covered, “liquid-solid” and “gas-solid”, where different particles cleaners are studied, are also contained within the index. Although undoubtedly, the most important point of them all is “separation with reaction”, as it is becoming quite relevant industrially speaking. A reaction takes place within the separation system, and then valuable products are separated by the ceramic membrane. The last applications described correspond to some specific applications which are not already industrially established. Modified Electro-dialysis system and ceramic membranes used as heat exchange or in the medical field as a bone regeneration method are some of them. Finally, the review article concludes with future important development on this field being discussed.

An extensive survey of the literature published in analytical and pharmaceutical chemistry journals has been conducted and the TLC methods which were developed and used for determination of non-steroidal anti-inflammatory drugs (NSAIDs) and cephalosporin antibiotics in bulk drugs, formulations and biological fluids have been reviewed. This review covers the time period from 1990 to 2008 during which over 120 TLC methods were reported. Presented review highlighted some recent patent developments and new TLC techniques that have been used in the analysis and detection of two different kinds of drugs.

The catalytic property of spinel MgCr2O4 was widely studied for combustion oxidation of the organic compound. The catalytic and photocatalytic activity of the MgCr2O4 powder at room temperature were studied in this work. The experiments revealed that the powder has a slow decomposition of methyl orange in dark and fast reductive photocatalytic degradation in light irradiation of 40W-fluorescent lamp. High initial pH of the solution is favorable for reducing decomposition of methyl orange either in dark or in light irradiation. The present article discusses some important patents related to the catalysis of Mg-containing spinel compounds.

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 chemicals, raw materials, materials, machines, design methods, chemical processes and techniques involved and related to chemical engineering.