Both but from envt point of view alkaline peroxide is best from pollution point of view and brightness benefit, but cost and conditions to be optimised keeping all aspects in mind

thank u sir but i have to mention which was gives the best between these 2 pulpings

As Sanjay rightly pointed, chlorine and sulphur containing compounds are not considered to be eco-friendly. Hence, AHP is the best among two methods of pulping.

Strength would be declined when the pulping agent attract the cellulose structure. Other wise no  effect may be shown by both of them as a pulping agent excluding environmental and cost effective fact. 

As both mentoned methos are based on  alkaline conditions of pulping, I gues the sulphite method will be more effective from viewpoint of raw material delignification.  Tremperature of this process can be higher as compared with that using NaOH/H2O2 and thus time of delignification shorter. Disadvantage of alkaline sulphite pulping is its higher negative environmental impact.

The mechanical properties of  both /peroxide and sulphite/ pulps prepared under identical conditions may be almost the same.

We can not say, depending on the end product. If writing and printing paper bleachinf stage is also required with sulphite pulping and In AHP both pulping and bleaching are in single stage. Strength is better for sulphite, envt AHP is best

The most remarkable facts have been previously exposed by other colleagues. I would add that both impregnation methods (I prefer avoid pulping methods) are employed to produce high/medium yield pulps, in combinatior with a further mechanical defibering stage(s).

For these kind of pulps, mechanical strength is not as relevant as the optical properties: brightness and britness reversion, because these pulps are usually aimed to graphic papers

Probably the question is not pertaining to high yield alkaline sulphite and alkaline peroxide chemical mechanical pulping. In our study on alkaline peroxide, pulping and bleaching stages are done in single stage with adequate strength properties with desired brightness gain The study was carried out with Poplar and the findings are published in IPPTA

As already mentioned in previous comments, the alkaline peroxide process is a high-yield process, so delignification is not a feature to consider.

In the case of alkaline sulfite pulping, the process is much more versatile and, if more severe conditions are used, higher delignification can be obtained.

However, as opposed to softwoods, the action of sodium hydroxide on hemicelluloses is considered as essential for bagasse, grasses and hardwoods. Both H2O2 and sulfite are added in small amounts, and with the objective of protecting brightness rather than improving mechanical properties.

In this case, the alkaline peroxide process is more environmentally friendly, its energy consumption in the refiner is much lower (since the Impresafiner destructure the material in previous stages) and semi-bleached pulp is obtained.

In brief, the main advantage of alkaline peroxide process is energy saving, rather than pulp strength (although it is good), and its main disadvantage is the high investment cost.

Yes i agree with comments of  Maria

Sartaj, which nonwood species are you asking about.  While there are many good answers above, not all nonwood species react the same.

I 

R Hurter i am taking of herbaceous species

Sartaj,  herbaceous plants by definition are are plants with non-woody stems.  They include annuals, biennials and perennials. They have varied underground plant parts (roots, bulbs, etc.).

This is too broad a definition as it includes decorative flowers, cereal straws, sugarcane bagasse, sorghum, Agaves, banana plants (Musa species) etc.

Not only strength properties vary, but there are other issues.  For example, wheat straw APMP produces a yellow pulp whereas sulphite produces a beige pulp.

You need to be more specific.

thank you sir  to be more specific i utilizes datura stem for paper making using soda and alkaline peroxide pulping and sulphite pulping now i wants to clear this which pulp have better strength properties sulphite or alkaline peroxide as i said in question

Sartaj,  thank you for your reply.  Although I have been working with nonwoods for 36 years, Datura stramonium is a new one for me.  Also, mechanical pulping of nonwoods not widely used.

If you consider wheat straw full chemical pressurized pulping for bleachable grades, monosulphite cooking gives a higher yield, about 52-55% unscreened, versus 44-46% for caustic soda.  But, the sulphite pulp is a little weaker than the soda pulp.

And, if you consider high yield semichemical atmospheric puling, the trend is similar - sulphite has a higher yield but slightly lower strength.

I suspect that the trend will be similar for mechanical pulp.

Hope this helps.

Bob

thank you hurter sir

Sartaj,  I should have also mentioned that the yield difference for mechanical pulp likely is small as compared to chemical pulp so likely will not be a significant factor.  Also, sulphite tends to give a lighter color which may be preferred.

Bob

Some answers are provided in the below mentioned research. Best wishes to you all.

https://www.researchgate.net/publication/315427845_Agricultural_Residues_Wastes_for_Manufacture_of_Paper_Board_and_Miscellaneous_Products_Background_Overview_and_Future_Prospects?_sg=3xcP2-HPPJ1eb2_t2Uw6mF6C-4M2xMbM_CcT_trFXXZxmGKkFkm1OT9iPvAO2gkoughcdaAIVO7mQwyZn-u88qA0lMpEXByNtoPgFaoM.dmqjskGLo5E6-yGTf2zFA6-sNhe7aLK60RegMQcrkvGofjRigwikOKgT5-O6ptgJ-ILj-r92zF3tANqAGp305w

The below mentioned researcher has many articles on pulping of non-wood and wood biomass. Happy new year.

https://www.researchgate.net/profile/Yehia_Fahmy